Help: GIS

[zxo102]

Hi,
    I am new in GIS area and need your suggestions for where I can
start from.  I have a python based web application with a database.
Now I would like to add a GIS map into my application. When a user
clicks a certain area in the GIS map, it can grab the data from the
database via my python based application. Do I have to use MapServer
or Grass or some other  backends for this purpose?
   Thanks  a lot.

Ouyang